Cherry Picker's List:
1964 The Accented Hair variety has sharply incised hair above Kennedy's ear and is found only as a Proof. The Doubled Die obverse is available both as a circulation strike and as a Proof. The Doubled Die reverse is known only in Proof.
1964-D Doubled Die obverse and Doubled Die reverse varieties exist.
1974-D Look for the Doubled Die Obverse varieties.
1776-1976 Four Proofs were struck without mint marks.
1979-S Issued only in Proof Sets. The "Type I" has an indistinct mint mark that looks like a blob. The mint mark on the "Type 2" is clear and distinct.
SPECIFICATIONS:
Designer: Obverse by Gilroy Roberts; reverse by Frank Gasparro
Diameter: 31 millimeters
Metal content:
Silver - 90%
Copper - 10%
Weight: 193 grains (12.5 grams)
Edge: Reeded
Mint mark: None (for Philadelphia, PA)
left of the stem of the olive branch on the reverse
90% SILVER PLANCHETS (1964 ONLY)
40% SILVER (CLAD) PLANCHETS (1965-1970)
COPPER-NICKEL CLAD COINAGE (1971-DATE)
Designer: Obverse by Gilroy Roberts; reverse by Frank Gasparro
Diameter: 31 millimeters
Metal content:
Outer layers - 75% Copper, 25% Nickel
Center - 100% Copper
Weight: 175 grains (11.3 grams)
Edge: Reeded
Mint mark: "S" (for San Francisco, CA) centered above the date
BICENTENNIAL REVERSE (1975-1976)
Designer: Obverse by Gilroy Roberts; reverse by Seth Huntington
Diameter: 31 millimeters
Metal Content:
Outer layers - 80% Silver, 20% Copper
Center - 79% Copper, 21% Silver
Weight: 178 grains (11.5 grams)
Edge: Reeded
Mint mark: "S" (for San Francisco, CA) centered above the date
NORMAL REVERSE RESUMED (1977-DATE)